I got my Sunlite XLs mounted on my bike. Wasn't too bad a job if you've ever changed bike tires before. Biggest hassle is getting the rear wheel on and off (if you don't have a service stand to hold the bike - I don't). I didn't want to turn the bike upside down cuz there is so much stuff on the handlebars, so I cobbled up a "bike lift". I know - looks unstable - but it worked!
I'm really pleased with the tires. They look just like motorcycle tires, and really change the look of the bike. Losing the big white letters on the sidewall makes it look less like a kid's bike, in my opinion. They completely eliminate the vibration and drag caused by the knobbies. They weigh almost exactly the same as the stock tires, so no change there. They are the same width as the old tires, but have a slightly smaller diameter. This makes the bike sit a little lower to the ground, which is good for me. It also makes a slight change in the gearing so I pedal a little faster at any given speed. I thought they would make less noise, but turns out they are just as noisy. Might just be the crappy rough pavement we have in our neighborhood. Haven't tried them yet on really smooth roads.
One thing I wasn't happy with was the way they were shipped to me by Niagara Cycle. The tires have a wire bead, and I thought they would be shipped flat in a box. Instead they were folded up double and shoved in a plastic bag with the 2 tubes. When I took them out of the bag and cut the tape, they didn't want to straighten out. The wire bead was bent pretty bad in a couple spots. I put them out in the hot sun for a whole day, but they still didn't completely flatten out. Because of the mangled bead, it was hard to get the tires to mount straight on the rim. After I got them mounted, I aired them up to 35 psi and let them sit overnight. Next day I let all the air out and readjusted them and finally got them pretty straight. If I was ordering any more tires online, I would offer to pay extra shipping charges just to get them shipped flat in a box.
All in all, very happy with the change. Next step is a 11-28 freewheel, to slow down my pedal cadence.